Air Quality

Ultrafine Particulate Matter

Background & Policy Context

Ultrafine particles are produced in large numbers by combustion activities (including vehicle emissions & wildfire) but their extremely small size means that they are currently unregulated by state and federal mass-based air quality regulations (PM 2.5 and PM 10).

An ultrafine particle is defined as having a diameter of less than 100 nanometers (nm). The average size particle from vehicle emissions is 25 nm, which is one million times smaller than a single particle of PM 2.5 dust. These ultrafine particles are undetectable using traditional optical particle counters (like PurpleAir), but are more mobile in the human body than larger particles, and thus may pose a greater risk to human health.

RESEARCH NEEDS

Research that supports the establishment of a health protective regulatory framework for ultrafine particulate matter, such as:

Research to develop and utilize innovative methods to measure ultrafines in the environment and to assess their health impacts, particularly in overburdened, marginalized communities.
Research on effective mitigation strategies to reduce exposure to ultrafines and improve related public health outcomes.

CAC members working on this issue

California Office of Health Hazard Assessment: Press Release: Study Finds Long-term Exposure to Ultrafine Particle Air Pollution Associated With Death From Heart Disease

References and Additional Reading

Air Toxics

Background & Policy Context

Air toxics (e.g., perchloroethylene, methylene chloride, dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead compounds) are addressed through the Clean Air Act, but are not currently included in the EPA’s National Ambient Air Quality Standards (NAAQS), which only apply to six common air pollutants that the EPA refers to as Criteria Air Pollutants. Some, but not all, Air Toxic emissions are regulated under the EPA’s National Emissions Standards for Hazardous Air Pollutants (NESHAP) . Both these lists are subject to periodic revision.

RESEARCH NEEDS

Research that increases knowledge of the health impacts of Air Toxics and how to mitigate any harmful effects, such as:

Research on the health impacts of different Air Toxics individually, in complex mixtures, and cumulatively (over time).
Research analyzing the usage and effectiveness of the EPA's Air Toxics Screening Assessment Tool (AirToxScreen ) to improve public health outcomes.
Research on effective strategies (regulatory, clinical, or behavioral) for reducing exposures to Air Toxics and/or mitigating the health impacts of exposure.

CAC members working on this issue

California EPA Office of Environmental Health Hazard Assessment: Air Toxics Hot Spots Reporting
California Department of Pesticide Regulation: Toxic Air Contaminant Program

References and Additional Reading

Air Quality Monitoring and Notifications

Background & Policy Context

Air quality monitoring is a central part of air quality policy management. Historically, public air quality monitoring systems have tended to cover large geographic regions and not have easily accessible formats. More recently, various public and private air quality notification systems have been developed to try to make air quality information available to the public in real time, allowing health protective action. These include the Air Quality Flag Program, Spare the Air alerts, and mobile apps and websites like AirNow, IQAir, and Breezometer, as well as public agency systems such as the San Joaquin Valley Air Pollution Control District’s Real-Time Air Advisory Network (RAAN) and the California Air Resources Board’s AB 617 Air Mapping Tool.

In addition to public agency and private air monitoring, a new generation of community-based air quality monitoring is rising as part of the environmental justice and health equity movement. These include the national PurpleAir network, California’s IVAN Air Monitoring Network, facilitated by EHSC CAC-members Comite Civico del Valle, and the SJVAir Collaborative, co-operated by a collaborative of EJ groups, including EHSC CAC-members Central California Asthma Collaborative and Central California Environmental Justice Network.

Both the IVAN Air Monitoring Network and SJVAir Collaborative allow users to view maps and individual monitors online also and sign up to receive alerts associated with monitors anywhere in the network. These networks can also be used to generate reports to guide enforcement actions by public agencies. However, little research has been done on how effective these tools are at improving public health outcomes - particularly in marginalized communities - and how they could be improved.

Some of the challenges facing agency-based air quality monitoring and notification include designing systems that are culturally-response and publically accessible in the diverse and overburdened communities that need them most. Conversely, community-based monitoring and notification systems often struggle with issues of quality assurance and quality control (QA-QC), data interpretation, integration with public systems, and long-term sustainable funding.

RESEARCH NEEDS

Research that supports the establishment of public air quality notifications that are timely, culturally appropriate, and effective in improving public health outcomes, such as:

Research on effective, accessible, culturally appropriate health risk communications in heavily impacted and marginalized communities, including farmworkers and other outdoor workers.
Research on the utilization of air quality alerts in a policy context to protect outdoor workers and other sensitive populations.
Research on safe, effective strategies for outdoor workers and other vulnerable populations to respond to public notices about exposure to poor air quality in high heat and poor air quality settings.
Research on the development of low-cost and mobile air quality monitors usable for community-based science.
Research on methods of integrating community- agency-based air quality monitoring data.
Research on effective, community-based analysis and communication of monitoring data in advocacy and public health contexts.

CAC members working on this issue

Central California Environmental Justice Network: Community Based Air Monitoring + AB617
Comite Civico del Valle: IVAN Community Air Monitoring Network in Imperial Valley, CA
Central California Asthma Collaborative: SJVAir Collaborative
California EPA Department of Toxic Substances Control: Community Air Monitoring Plan Guidance (2020)
Californians for Pesticide Reform Comment Letter: Development of a statewide pesticide notification system. Also signed by CAC members Central California Environmental Justice Network and Leadership Counsel for Justice and Accountability.
California Air Resources Board: Community Air Monitoring Program

References and Additional Reading

Oil and Gas Setbacks

Background & Policy Context

Prior to 2024, California did not have setback requirements for oil and gas drilling, unlike most other oil-producing states. Community advocates have worked for years to establish these setbacks, including AB 345 in 2019 and AB467 in 2021, both of which died in committee [3, 4], and SB 1137, which was passed in 2022, but was only active for a month before a referendum to overturn it was filed by the oil and gas industry (6). This ballot initiative was withdrawn on July 27, 2024, and the setback statute went back into effect that same day (7]. Industry representatives have said they now intend to challenge the law in court instead of via the legislative process [8].

Development of SB 1137. In 2021, the Department of Conservation’s Geologic Energy Management Division (CalGEM) convened a national Public Health Science Advisory Panel to review the scientific evidence on the public health implications of oil and gas production. Following their report, which found consistent evidence of harm within 1 kilometer of drilling operations, CalGEM released draft public health regulations. These regulations proposed a 3200 foot setback from sensitive locations (residences, schools, businesses, health care facilities, and other residential and long term care facilities including prisons) within which no new operations could be developed and additional emissions monitoring would be required of existing operations. It is estimated that 30% of California’s current oil and gas production takes place within the 3200 foot setback, and critics of the rule say it needs to do more to phase out existing production within the setback to protect public health (12, 13).

The setback regulations developed by CalGEM were expected to take effect in 2023. However, in August 2022 California Governor Gavin Newsom asked the legislature to consider adopting a law establishing the setbacks, rather than continuing through the lengthy regulatory process. The legislature subsequently passed SB 1137, establishing setbacks as part of a package of climate legislation signed by the governor in September 2022. The law was set to go into effect on January 1, 2023, however a veto referendum was filed one month later, putting enforcement of the law on hold until after the election. The referendum was withdrawn on July 27, 2024, at which point the statute immediately went into effect [7]. It is expected that the law will continue to face legal challenges via the court system. [8]

In addition to state efforts, Los Angeles adopted an Oil and Gas Drilling Ordinance in 2022 that would phase out oil and gas drilling in the city over the next two decades (17, 18, 19, 20). This ordinance was struck down in on September 12, 2024 by a county judge on the grounds that the state, rather than the city, has jurisdiction over drilling operations [21, 22]. However this ruling was invalidated two weeks later when the governor signed AB 3233, which gives California cities and counties the right to ban drilling and phase out existing wells [23].

RESEARCH NEEDS

Research on the health impacts of oil and gas production with SB 1137 setbacks in place, such as:

Research on the potential or actual health benefits of various engineering controls to reduce emissions from existing wells, particularly those within the 3200 foot setback of sensitive locations.
Research on the health impacts of SB 1137 implementation, including compliance assessment.

CAC members working on this issue

Central California Environmental Justice Network:
- Support SB 1137 - Setbacks Must Be A Part of California’s Pro-Worker Climate Agenda: A Letter from (GreenPeace USA) and Nayamin Martinez (Central California Environmental Justice Network) to the California State Legislature and Governor’s Office
- Abandoned & Idled Wells Pose Significant Safety Threats to Frontline Communities Across CA After Decades of Neglect

References and Additional Reading

AB 617 Implementation

Background & Policy Context

The AB 617 Community Air Protection Program was passed in 2018 with the purpose of improving air quality in heavily impacted communities in California. It involves community-scale air quality monitoring and the development of air pollution emission reduction plans. The California Air Resources Board (CARB) manages the program for the state, and local Air Districts are responsible for implementation in consultation with Community Steering Committees made up of local residents, organizations, governments, and businesses.

CARB’s Community Air Protection Program Blueprint (Blueprint 2.0) includes both a strategic plan for the program and practical guidance for partners engaged in improving air quality at the local level. The Program Blueprint was originally established in 2018 when the law was enacted and is required to be updated every 5 years. CARB’s Governing Board approved the Blueprint 2.0 in October, 2023.

Many CAC members are closely involved with AB 617 implementation and are organizing to ensure quality community engagement and advocating for improvements to the regulation.

RESEARCH NEEDS

Research that determines if (and how) AB 617 implementation is improving public health outcomes in participating communities, such as:

Measurement of changes to air quality associated with AB 617 implementation and/or specific mechanisms being utilized in participating communities.
Analysis of changes to public health outcomes associated with AB 617 implementation, in particular using the health metrics currently under development by CARB.
Examination of the role of land use (e.g., restricting certain land uses in already heavily impacted communities), urban greening, trade-ins for domestic equipment such as lawnmowers and fireplaces and other methods as public health interventions to improve air quality and associated health outcomes.
Research on the development of community-based air quality monitoring and integration with public agency monitoring systems. (see separate section on air quality monitoring.)
Public pesticide notification systems (see separate section on pesticide notification)

CAC members working on this issue

Central California Environmental Justice Network: Community Based Air Monitoring + AB617
Comite Civico del Valle: IVAN Community Air Monitoring Network in Imperial Valley, CA
Californians for Pesticide Reform: Advance Notice of Pesticide Use in Shafter, CA
Leadership Counsel for Justice and Accountability: Eastern Coachella Valley residents, make the case for state help cleaning up your air
California Air Resources Board: Blueprint 2.0 Revision Update

References and Additional Reading

Wildfire Smoke

Background & Policy Context

Wildfire is a major environmental health concern in California, where in recent years record heat and drought have increased their size, speed, and destructiveness. In response, billions of dollars of new investments are being made in preventing and responding to wildfires at both the state and federal level (2,3,4), including SB109, which established a new Office of Wildfire Technology Research and Development .

These large, rapidly spreading fires are now also crossing into more populated areas. As more industrial and household materials burn, the composition of wildfire smoke is changing and may include toxic metals and other contaminants.

Residents of California's Central Valley are particularly vulnerable to wildfire smoke exposure. Smoke from fires in the mountains can collect and settle in the Valley for days or weeks at a time, leaving residents exposed in some cases for longer than those in the actual fire zone. Central Valley communities already face some of the worst air pollution in the country and many residents are low income, non-English speaking, and have limited access to mitigations like air purifiers, HVAC systems, masks, or the option of staying or working indoors (13,14).

The region is also home to the largest agricultural sector in the country, including half of its agricultural workers, who work outside during fire season with minimal protections, while also facing high rates of occupational illness and injury and limited access to health care.

RESEARCH NEEDS

Research on the impact of prolonged wildfire smoke exposure on the health of communities in the Central Valley, such as:

Research on the environmental health impacts of wildfire smoke exposure on outdoor workers. Research on effective exposure mitigation strategies in high risk occupational settings, like agricultural field work and construction.
Research on the environmental health impacts of wildfire smoke exposure in communities also experiencing high levels of air pollution from other sources.
Research on effective wildfire smoke mitigation strategies in sensitive locations like schools, day care centers, prisons, nursing homes, and other institutional and medical settings.

CAC members working on this issue

Central California Asthma Collaborative: CARB-Funded Research Study on the Impacts of Repeated Short-Term Wildfire Smoke Exposure
California Department of Public Health: Wildfire Smoke and Ash Impacts on Public Health
California EPA Office of Environmental Health Hazard Assessment Report: Wildfire Smoke: A Guide for Public Health Officials (2019)
Leadership Counsel for Justice and Accountability: Crucial and Critical: Invest now in Community Resilience, Public Health, and Emergency Response
Central California Environmental Justice Network: California EPA grant to train farmworkers on the health impacts of wildfire smoke exposure.
California Air Resources Board: Smoke Ready California; California Smoke Spotter App (Apple, Google)